Method of making compound sponge rubber and fabric articles



Oct. 18,1927. 1,645,604

M. s. LOWER METHOD OF MAKING COMBOUND SPONGE RUBBER AND FABRIC ARTICLES Filed March 5, 1927 /I//I/I//I//[/I/Il/ I Il/ /II/ ,III/I(IIIIIIIIIIl/IIIIIIIIIII/IIIIIIIII/IIIIIIIIIIIIIIIIIIII A V /l/l//l I /////Y [/l/ll zin :I: sii? IN VEN TOR.

MELVIN Lows BY www A TTORNEY Patentecl Oct. 18, 1927.

UNITED STATES '1545504 PATENT OFFICE.

MELVIN S. LOWER, OF BARBERTON, OHIO. ASSIGNOR TO THE SUN RUBBER COMPANY,

' OF BARBERTON, OHIO, A CORPORATIN OF OHIO.

METHOD OF MAKING COMPOUND SPONGE RUBBER AND FABIIC .ARTICLES.

Application filed March 3,'1927. Serial No. 172,4o5.

This invention relates to the manufacture of fabric covered rubber articles, particularly articles nade of sponge rubber with a felt or ornamental fabric covering. The object of the invention isto manufacture an article having tapered or feathered edges or other irregular shapes, and to insure an even stretched covering of fabric over the rubber to present a neat and attractive article. In the particular embodiment which is illustrated here, the invention is shown as applied to the manufacture of chair pads, although it may be applied to the manufacture of other articles as well. The chair pad or other article which is to be made by this process is superior to fabric covered articles of this nature nade by other processes', as the fabric is stretched about its entire surface so that a smooth and even application of the fabric is attained without special attention on the part of the manufact-uroi'.

In prior p-rocesses attempts have been made to secure an even application and stretching of the fabric covering on sponge rubber articles by stretching the beveled or tapered edge portions only. The present invention has for its object the stretching of the fabric covering about the entire surface of the article thus securing more perfect manufacture and better quality of workmanship. In addition the process does not require special equipment but may be carried out with less expense than prior processes.

In the drawings in which the best known methodof practicing the invention is illustrated: i

Figur-e 1 is a cross sectional View of two heated press plates with the article placed therein ready for vulcanization;

F igure 2 is a similar View showing the article as vulcanized;

Figure 3 is a plan of the article with the edges untrimmed; and

Figure 4 is a cross section of the finished article.

In the drawings 1 represents the lower platen and 2 the upper platen of a heated Vulcanizing press, both of which platens are fabric-covered for the escape of gases generated during the curing operation. In order to manufacture the cushion or other article, a slab of uncured rubber 3, preferr ably of a composition which will expand in heating to form sponge rubber, is cut to the proper size and shape and over one surface is laid the fabric covering 4 which is to be secured to the article. This may be felt, velour, canvas or other fabric or covering material which will stretch. In this process it is not necessary or advisable to treat the surface with a solvent or kerosene before the application of the fabric covering.

The fabric covering is somewhat larger than the body of the rubber and projects outwardly therefrom about the entire circumference of the article.

The compound sheet as shown in F igure 1 is laid upon the platen 1 with the fabric covering upwardly, and about the slab of rubber is placed a frame 6 which is the shape of the article to be formed. By this process the use of all molds is avoided, thus simplifying and reducing the cost of the Operations.

The platens 1 and 2 are brought together by hydraulic or other pressure which serves to clamp the edges of the sheet of oovering material. The article is retainecl in the mold for a sufiicient time to cure. lVhen the stock is vulcanized it will expand to several times its original Volume. This action is illustrated in Figure 2 in which the expanded sponge rubber is shown filling the space between the platens except about the edges. It will be seen that the expansion of the rubber, due to the fact that the fabric is spaced from the platen about its entire surface, will .stretch the whole extent of the covering fabric and smoothly apply it to the sponge rubber, which will soften and adhere by the heat and during the process of vulcanization.

The article which is obtained is removed from the mold and the edges trimmed, presenting the perfected article shown in Figure 4 in which the fabric is stretched about the entire surface 8 and upon the edges. No rubber will escape during vulcanization and the fabric only is required to be trimmed from about the edges. The edges 10 will acquire the smooth and even curvature imparted by the expansion of the rubber material and Will not be confined by a mold surface as in examples of the prior art.

WVhat is claimed is:

The process of manufacturing laninated sponge rubber and fabric articles having rounded edges, conprising forming a slab of ruhhe' compounded to expancl and form sponge 'uhbe' on vulcanzation, layng a sheet of fab'c over the slab, securng the edges ot' the 'ah'c about the perphe'y of the. rubber slab, placing the article within a closed chanhe' With the fabric out of conlac-t with the walls the'eo', and subjectng the slab to Vulcanizng temperature fol` a sufficent period to cause the rubber to expand and to Stretch the 't'ab-ic during vulcanization over its entire surface and allowing the 'ab'c to assume a natural curvature about the edges ot' the slab While the fabre about the edges of the slab is out of contact with the walls of the chanbe'.

MELVIN S. LOWER. 

